Struct BumpScope 

pub struct BumpScope<'a, A = Global, const MIN_ALIGN: usize = 1, const UP: bool = true, const GUARANTEED_ALLOCATED: bool = true, const DEALLOCATES: bool = true> { /* private fields */ }

A bump allocation scope.

A BumpScope’s allocations are live for 'a, which is the lifetime of its associated BumpScopeGuard(Root) or scoped closure.

BumpScope has the same allocation api as Bump. The only thing that is missing is reset and methods that consume the Bump. For a method overview and examples, have a look at the Bump docs.

This type is provided as a parameter to the closure of Bump::scoped, BumpScope::scoped or created by BumpScopeGuard::scope and BumpScopeGuardRoot::scope. A Bump can also be turned into a BumpScope using as_scope, as_mut_scope or into.

Implementations

impl<'a, A, const MIN_ALIGN: usize, const UP: bool, const DEALLOCATES: bool> BumpScope<'a, A, MIN_ALIGN, UP, true, DEALLOCATES>

where MinimumAlignment<MIN_ALIGN>: SupportedMinimumAlignment,

Methods for a guaranteed allocated BumpScope.

pub fn allocator(&self) -> &'a A

Returns a reference to the base allocator.

pub fn scoped<R>( &mut self, f: impl FnOnce(BumpScope<'_, A, MIN_ALIGN, UP, true, DEALLOCATES>) -> R, ) -> R

Calls f with a new child scope.

Examples

let mut bump: Bump = Bump::new();

bump.scoped(|bump| {
    bump.alloc_str("Hello, world!");
    assert_eq!(bump.stats().allocated(), 13);
});

assert_eq!(bump.stats().allocated(), 0);

pub fn scoped_aligned<const NEW_MIN_ALIGN: usize, R>( &mut self, f: impl FnOnce(BumpScope<'_, A, NEW_MIN_ALIGN, UP, true, DEALLOCATES>) -> R, ) -> R

where MinimumAlignment<NEW_MIN_ALIGN>: SupportedMinimumAlignment,

Calls f with a new child scope of a new minimum alignment.

Examples

let mut bump: Bump = Bump::new();

// bump starts off by being aligned to 16
assert!(bump.stats().current_chunk().bump_position().is_aligned_to(16));

// allocate one byte
bump.alloc(1u8);

// now the bump is only aligned to 1
// (if our `MIN_ALIGN` was higher, it would be that)
assert!(bump.stats().current_chunk().bump_position().addr().get() % 2 == 1);
assert_eq!(bump.stats().allocated(), 1);

bump.scoped_aligned::<8, ()>(|bump| {
   // in here, the bump will have the specified minimum alignment of 8
   assert!(bump.stats().current_chunk().bump_position().is_aligned_to(8));
   assert_eq!(bump.stats().allocated(), 8);

   // allocating a value with its size being a multiple of 8 will no longer have
   // to align the bump pointer before allocation
   bump.alloc(1u64);
   assert!(bump.stats().current_chunk().bump_position().is_aligned_to(8));
   assert_eq!(bump.stats().allocated(), 16);
    
   // allocating a value smaller than the minimum alignment must align the bump pointer
   // after the allocation, resulting in some wasted space
   bump.alloc(1u8);
   assert!(bump.stats().current_chunk().bump_position().is_aligned_to(8));
   assert_eq!(bump.stats().allocated(), 24);
});

assert_eq!(bump.stats().allocated(), 1);

pub fn aligned<const NEW_MIN_ALIGN: usize, R>( &mut self, f: impl FnOnce(BumpScope<'a, A, NEW_MIN_ALIGN, UP, true, DEALLOCATES>) -> R, ) -> R

where MinimumAlignment<NEW_MIN_ALIGN>: SupportedMinimumAlignment,

Calls f with this scope but with a new minimum alignment.

Examples

Increase the minimum alignment:

let mut bump: Bump = Bump::new();
let bump = bump.as_mut_scope();

// here we're allocating with a `MIN_ALIGN` of `1`
let foo = bump.alloc_str("foo");
assert_eq!(bump.stats().allocated(), 3);

let bar = bump.aligned::<8, _>(|bump| {
    // in here the bump position has been aligned to `8`
    assert_eq!(bump.stats().allocated(), 8);
    assert!(bump.stats().current_chunk().bump_position().is_aligned_to(8));

    // make some allocations that benefit from the higher `MIN_ALIGN` of `8`
    let bar = bump.alloc(0u64);
    assert_eq!(bump.stats().allocated(), 16);
  
    // the bump position will stay aligned to `8`
    bump.alloc(0u8);
    assert_eq!(bump.stats().allocated(), 24);

    bar
});

assert_eq!(bump.stats().allocated(), 24);

// continue making allocations with a `MIN_ALIGN` of `1`
let baz = bump.alloc_str("baz");
assert_eq!(bump.stats().allocated(), 24 + 3);

dbg!(foo, bar, baz);

Decrease the minimum alignment:

let mut bump: Bump<Global, 8> = Bump::new();
let bump = bump.as_mut_scope();

// make some allocations that benefit from the `MIN_ALIGN` of `8`
let foo = bump.alloc(0u64);

let bar = bump.aligned::<1, _>(|bump| {
    // make some allocations that benefit from the lower `MIN_ALIGN` of `1`
    let bar = bump.alloc(0u8);

    // the bump position will not get aligned to `8` in here
    assert_eq!(bump.stats().allocated(), 8 + 1);

    bar
});

// after `aligned()`, the bump position will be aligned to `8` again
// to satisfy our `MIN_ALIGN`
assert!(bump.stats().current_chunk().bump_position().is_aligned_to(8));
assert_eq!(bump.stats().allocated(), 16);

// continue making allocations that benefit from the `MIN_ALIGN` of `8`
let baz = bump.alloc(0u64);

dbg!(foo, bar, baz);

pub fn scope_guard( &mut self, ) -> BumpScopeGuard<'_, A, MIN_ALIGN, UP, DEALLOCATES>

Creates a new BumpScopeGuard.

This allows for creation of child scopes.

Examples

let mut bump: Bump = Bump::new();

{
    let mut guard = bump.scope_guard();
    let bump = guard.scope();
    bump.alloc_str("Hello, world!");
    assert_eq!(bump.stats().allocated(), 13);
}

assert_eq!(bump.stats().allocated(), 0);

impl<'a, A, const MIN_ALIGN: usize, const UP: bool, const DEALLOCATES: bool> BumpScope<'a, A, MIN_ALIGN, UP, false, DEALLOCATES>

where MinimumAlignment<MIN_ALIGN>: SupportedMinimumAlignment,

Methods for a not guaranteed allocated BumpScope.

pub fn allocator(&self) -> Option<&'a A>

Returns a reference to the base allocator.

impl<'a, A, const MIN_ALIGN: usize, const UP: bool, const GUARANTEED_ALLOCATED: bool, const DEALLOCATES: bool> BumpScope<'a, A, MIN_ALIGN, UP, GUARANTEED_ALLOCATED, DEALLOCATES>

where MinimumAlignment<MIN_ALIGN>: SupportedMinimumAlignment,

Methods that are always available.

pub fn checkpoint(&self) -> Checkpoint

Creates a checkpoint of the current bump position.

The bump position can be reset to this checkpoint with reset_to.

Examples

let bump: Bump = Bump::new();
let checkpoint = bump.checkpoint();

{
    let hello = bump.alloc_str("hello");
    assert_eq!(bump.stats().allocated(), 5);
}

unsafe { bump.reset_to(checkpoint); }
assert_eq!(bump.stats().allocated(), 0);

pub unsafe fn reset_to(&self, checkpoint: Checkpoint)

Resets the bump position to a previously created checkpoint. The memory that has been allocated since then will be reused by future allocations.

Safety

• the checkpoint must have been created by this bump allocator
• the bump allocator must not have been reset since creation of this checkpoint
• there must be no references to allocations made since creation of this checkpoint
• the checkpoint must not have been created by an!GUARANTEED_ALLOCATED when self is GUARANTEED_ALLOCATED

Examples

let bump: Bump = Bump::new();
let checkpoint = bump.checkpoint();

{
    let hello = bump.alloc_str("hello");
    assert_eq!(bump.stats().allocated(), 5);
}

unsafe { bump.reset_to(checkpoint); }
assert_eq!(bump.stats().allocated(), 0);

pub fn stats(&self) -> Stats<'a, A, UP, GUARANTEED_ALLOCATED>

“Returns a type which provides statistics about the memory usage of the bump allocator.

pub fn into_not_guaranteed_allocated( self, ) -> BumpScope<'a, A, MIN_ALIGN, UP, false, DEALLOCATES>

Converts this BumpScope into a not guaranteed allocated BumpScope.

pub fn as_not_guaranteed_allocated( &self, ) -> &BumpScope<'a, A, MIN_ALIGN, UP, false, DEALLOCATES>

Borrows BumpScope as a not guaranteed allocated BumpScope.

Note that it’s not possible to mutably borrow as a not guaranteed allocated bump allocator. That’s because a user could mem::swap it with an actual unallocated bump allocator which in turn would make &mut self unallocated.

pub fn into_raw(self) -> NonNull<()>

Converts this BumpScope into a raw pointer.

pub unsafe fn from_raw(ptr: NonNull<()>) -> Self

Converts the raw pointer that was created with into_raw back into a BumpScope.

Safety

This is highly unsafe, due to the number of invariants that aren’t checked:

• ptr must have been created with Self::into_raw.
• This function must only be called once with this ptr.
• The lifetime must be the original one.
• Nothing must have been allocated since then.

pub fn as_mut_aligned<const NEW_MIN_ALIGN: usize>( &mut self, ) -> &mut BumpScope<'a, A, NEW_MIN_ALIGN, UP, GUARANTEED_ALLOCATED, DEALLOCATES>

where MinimumAlignment<NEW_MIN_ALIGN>: SupportedMinimumAlignment,

Mutably borrows BumpScope with a new minimum alignment.

This cannot decrease the alignment. Trying to decrease alignment will result in a compile error. You can use aligned or scoped_aligned to decrease the alignment.

When decreasing the alignment we need to make sure that the bump position is realigned to the original alignment. That can only be ensured by having a function that takes a closure, like the methods mentioned above do.

pub fn as_scope(&self) -> &Self

Returns &self as is. This is useful for macros that support both Bump and BumpScope.

pub fn as_mut_scope(&mut self) -> &mut Self

Returns &mut self as is. This is useful for macros that support both Bump and BumpScope.

pub fn into_aligned<const NEW_MIN_ALIGN: usize>( self, ) -> BumpScope<'a, A, NEW_MIN_ALIGN, UP, GUARANTEED_ALLOCATED, DEALLOCATES>

where MinimumAlignment<NEW_MIN_ALIGN>: SupportedMinimumAlignment,

Converts this BumpScope into a BumpScope with a new minimum alignment.

This cannot decrease the alignment. Trying to decrease alignment will result in a compile error. You can use aligned or scoped_aligned to decrease the alignment.

When decreasing the alignment we need to make sure that the bump position is realigned to the original alignment. That can only be ensured by having a function that takes a closure, like the methods mentioned above do.

If this was allowed to decrease the alignment it would break minimum alignment:

let mut bump: Bump<Global, 8, true> = Bump::new();
let mut guard = bump.scope_guard();

{
    let scope = guard.scope().into_aligned::<1>();
    scope.alloc(0u8);
}

{
    let scope = guard.scope();
    // scope is not aligned to `MIN_ALIGN`!!
}

pub fn into_without_dealloc( self, ) -> BumpScope<'a, A, MIN_ALIGN, UP, GUARANTEED_ALLOCATED, false>

Turns off deallocation and shrinking.

pub fn as_without_dealloc( &self, ) -> &BumpScope<'a, A, MIN_ALIGN, UP, GUARANTEED_ALLOCATED, false>

Turns off deallocation and shrinking.

pub fn as_mut_without_dealloc( &mut self, ) -> &mut BumpScope<'a, A, MIN_ALIGN, UP, GUARANTEED_ALLOCATED, false>

Turns off deallocation and shrinking.

pub fn into_with_dealloc( self, ) -> BumpScope<'a, A, MIN_ALIGN, UP, GUARANTEED_ALLOCATED, true>

Turns on deallocation and shrinking.

pub fn as_with_dealloc( &self, ) -> &BumpScope<'a, A, MIN_ALIGN, UP, GUARANTEED_ALLOCATED, true>

Turns on deallocation and shrinking.

pub fn as_mut_with_dealloc( &mut self, ) -> &mut BumpScope<'a, A, MIN_ALIGN, UP, GUARANTEED_ALLOCATED, true>

Turns on deallocation and shrinking.

impl<'a, A, const MIN_ALIGN: usize, const UP: bool, const GUARANTEED_ALLOCATED: bool, const DEALLOCATES: bool> BumpScope<'a, A, MIN_ALIGN, UP, GUARANTEED_ALLOCATED, DEALLOCATES>

where MinimumAlignment<MIN_ALIGN>: SupportedMinimumAlignment, A: Allocator,

Methods that are always available. (but with A: Allocator)

pub fn into_guaranteed_allocated( self, f: impl FnOnce() -> Bump<A, MIN_ALIGN, UP, true, DEALLOCATES>, ) -> BumpScope<'a, A, MIN_ALIGN, UP, true, DEALLOCATES>

Converts this BumpScope into a guaranteed allocated BumpScope.

See Bump::into_guaranteed_allocated.

Panics

Panics if the closure panics.

pub fn try_into_guaranteed_allocated( self, f: impl FnOnce() -> Result<Bump<A, MIN_ALIGN, UP, true, DEALLOCATES>, AllocError>, ) -> Result<BumpScope<'a, A, MIN_ALIGN, UP, true, DEALLOCATES>, AllocError>

Converts this BumpScope into a guaranteed allocated BumpScope.

See Bump::try_into_guaranteed_allocated.

Errors

Errors if the closure fails.

pub fn as_guaranteed_allocated( &self, f: impl FnOnce() -> Bump<A, MIN_ALIGN, UP, true, DEALLOCATES>, ) -> &BumpScope<'a, A, MIN_ALIGN, UP, true, DEALLOCATES>

Borrows BumpScope as a guaranteed allocated BumpScope.

See Bump::as_guaranteed_allocated.

Panics

Panics if the closure panics.

pub fn try_as_guaranteed_allocated( &self, f: impl FnOnce() -> Result<Bump<A, MIN_ALIGN, UP, true, DEALLOCATES>, AllocError>, ) -> Result<&BumpScope<'a, A, MIN_ALIGN, UP, true, DEALLOCATES>, AllocError>

Borrows BumpScope as a guaranteed allocated BumpScope.

See Bump::try_as_guaranteed_allocated.

Errors

Errors if the closure fails.

pub fn as_mut_guaranteed_allocated( &mut self, f: impl FnOnce() -> Bump<A, MIN_ALIGN, UP, true, DEALLOCATES>, ) -> &mut BumpScope<'a, A, MIN_ALIGN, UP, true, DEALLOCATES>

Mutably borrows BumpScope as a guaranteed allocated BumpScope.

See Bump::as_mut_guaranteed_allocated.

Panics

Panics if the closure panics.

pub fn try_as_mut_guaranteed_allocated( &mut self, f: impl FnOnce() -> Result<Bump<A, MIN_ALIGN, UP, true, DEALLOCATES>, AllocError>, ) -> Result<&mut BumpScope<'a, A, MIN_ALIGN, UP, true, DEALLOCATES>, AllocError>

Mutably borrows BumpScope as a guaranteed allocated BumpScope.

See Bump::try_as_mut_guaranteed_allocated.

Errors

Errors if the closure fails.

impl<'a, A, const MIN_ALIGN: usize, const UP: bool, const GUARANTEED_ALLOCATED: bool, const DEALLOCATES: bool> BumpScope<'a, A, MIN_ALIGN, UP, GUARANTEED_ALLOCATED, DEALLOCATES>

where MinimumAlignment<MIN_ALIGN>: SupportedMinimumAlignment, A: BaseAllocator<GUARANTEED_ALLOCATED>,

Methods to allocate. Available as fallible or infallible.

pub fn alloc<T>(&self, value: T) -> BumpBox<'a, T>

Allocate an object.

Panics

Panics if the allocation fails.

Examples

let allocated = bump.alloc(123);
assert_eq!(allocated, 123);

pub fn try_alloc<T>(&self, value: T) -> Result<BumpBox<'a, T>, AllocError>

Allocate an object.

Errors

Errors if the allocation fails.

Examples

let allocated = bump.try_alloc(123)?;
assert_eq!(allocated, 123);

pub fn alloc_with<T>(&self, f: impl FnOnce() -> T) -> BumpBox<'a, T>

Allocates space for an object, then calls f to produce the value to be put in that place.

In some cases this could be more performant than alloc(f()) because it permits the compiler to directly place T in the allocated memory instead of constructing it on the stack and copying it over.

Panics

Panics if the allocation fails.

Examples

let allocated = bump.alloc_with(|| 123);
assert_eq!(allocated, 123);

pub fn try_alloc_with<T>( &self, f: impl FnOnce() -> T, ) -> Result<BumpBox<'a, T>, AllocError>

Allocates space for an object, then calls f to produce the value to be put in that place.

In some cases this could be more performant than try_alloc(f()) because it permits the compiler to directly place T in the allocated memory instead of constructing it on the stack and copying it over.

Errors

Errors if the allocation fails.

Examples

let allocated = bump.try_alloc_with(|| 123)?;
assert_eq!(allocated, 123);

pub fn alloc_default<T: Default>(&self) -> BumpBox<'a, T>

Allocate an object with its default value.

This is equivalent to alloc_with(T::default).

Panics

Panics if the allocation fails.

Examples

let allocated = bump.alloc_default::<i32>();
assert_eq!(allocated, 0);

pub fn try_alloc_default<T: Default>( &self, ) -> Result<BumpBox<'a, T>, AllocError>

Allocate an object with its default value.

This is equivalent to try_alloc_with(T::default).

Errors

Errors if the allocation fails.

Examples

let allocated = bump.try_alloc_default()?;
assert_eq!(allocated, 0);

pub fn alloc_clone<T: CloneToUninit + ?Sized>( &self, value: &T, ) -> BumpBox<'a, T>

Available on crate feature nightly-clone-to-uninit only.

Allocate an object by cloning it.

Unlike alloc(value.clone()) this method also works for dynamically-sized types.

Panics

Panics if the allocation fails.

Examples

Allocate a slice, str, CStr, Path:

#![feature(clone_to_uninit)]

use std::path::Path;

let cloned = bump.alloc_clone(&[1, 2, 3]);
assert_eq!(cloned, &[1, 2, 3]);

let cloned = bump.alloc_clone("foo");
assert_eq!(cloned, "foo");

let cloned = bump.alloc_clone(c"foo");
assert_eq!(cloned, c"foo");

let cloned = bump.alloc_clone(Path::new("foo"));
assert_eq!(cloned, Path::new("foo"));

Allocate a trait object:

#![feature(clone_to_uninit)]

use core::clone::CloneToUninit;

trait FnClone: Fn() -> String + CloneToUninit {}
impl<T: ?Sized + Fn() -> String + CloneToUninit> FnClone for T {}

// the closure references a local variable
let reference = &String::from("Hello,");

// and owns a string that it will have to clone
let value = String::from("world!");

let closure = move || format!("{reference} {value}");
let object: &dyn FnClone = &closure;

assert_eq!(object(), "Hello, world!");

let bump: Bump = Bump::new();
let object_clone = bump.alloc_clone(object);

assert_eq!(object_clone(), "Hello, world!");

pub fn try_alloc_clone<T: CloneToUninit + ?Sized>( &self, value: &T, ) -> Result<BumpBox<'a, T>, AllocError>

Available on crate feature nightly-clone-to-uninit only.

Allocate an object by cloning it.

Unlike alloc(value.clone()) this method also works for dynamically-sized types.

Errors

Errors if the allocation fails.

Examples

Allocate a slice, str, CStr, Path:

#![feature(clone_to_uninit)]

use std::path::Path;

let cloned = bump.try_alloc_clone(&[1, 2, 3])?;
assert_eq!(cloned, &[1, 2, 3]);

let cloned = bump.try_alloc_clone("foo")?;
assert_eq!(cloned, "foo");

let cloned = bump.try_alloc_clone(c"foo")?;
assert_eq!(cloned, c"foo");

let cloned = bump.try_alloc_clone(Path::new("foo"))?;
assert_eq!(cloned, Path::new("foo"));

Allocate a trait object:

#![feature(clone_to_uninit)]

use core::clone::CloneToUninit;

trait FnClone: Fn() -> String + CloneToUninit {}
impl<T: ?Sized + Fn() -> String + CloneToUninit> FnClone for T {}

// the closure references a local variable
let reference = &String::from("Hello,");

// and owns a string that it will have to clone
let value = String::from("world!");

let closure = move || format!("{reference} {value}");
let object: &dyn FnClone = &closure;

assert_eq!(object(), "Hello, world!");

let bump: Bump = Bump::try_new()?;
let object_clone = bump.try_alloc_clone(object)?;

assert_eq!(object_clone(), "Hello, world!");

pub fn alloc_slice_move<T>( &self, slice: impl OwnedSlice<Item = T>, ) -> BumpBox<'a, [T]>

Allocate a slice and fill it by moving elements from an existing slice.

Panics

Panics if the allocation fails.

Examples

// by value
let a = bump.alloc_slice_move([1, 2]);
let b = bump.alloc_slice_move(vec![3, 4]);
let c = bump.alloc_slice_move(bump.alloc_iter(5..=6));

// by mutable reference
let mut other = vec![7, 8];
let d = bump.alloc_slice_move(&mut other);
assert!(other.is_empty());

assert_eq!(a, [1, 2]);
assert_eq!(b, [3, 4]);
assert_eq!(c, [5, 6]);
assert_eq!(d, [7, 8]);

pub fn try_alloc_slice_move<T>( &self, slice: impl OwnedSlice<Item = T>, ) -> Result<BumpBox<'a, [T]>, AllocError>

Allocate a slice and fill it by moving elements from an existing slice.

Errors

Errors if the allocation fails.

Examples

// by value
let a = bump.try_alloc_slice_move([1, 2])?;
let b = bump.try_alloc_slice_move(vec![3, 4])?;
let c = bump.try_alloc_slice_move(bump.alloc_iter(5..=6))?;

// by mutable reference
let mut other = vec![7, 8];
let d = bump.try_alloc_slice_move(&mut other)?;
assert!(other.is_empty());

assert_eq!(a, [1, 2]);
assert_eq!(b, [3, 4]);
assert_eq!(c, [5, 6]);
assert_eq!(d, [7, 8]);

pub fn alloc_slice_copy<T: Copy>(&self, slice: &[T]) -> BumpBox<'a, [T]>

Allocate a slice and fill it by Copying elements from an existing slice.

Panics

Panics if the allocation fails.

Examples

let allocated = bump.alloc_slice_copy(&[1, 2, 3]);
assert_eq!(allocated, [1, 2, 3]);

pub fn try_alloc_slice_copy<T: Copy>( &self, slice: &[T], ) -> Result<BumpBox<'a, [T]>, AllocError>

Allocate a slice and fill it by Copying elements from an existing slice.

Errors

Errors if the allocation fails.

Examples

let allocated = bump.try_alloc_slice_copy(&[1, 2, 3])?;
assert_eq!(allocated, [1, 2, 3]);

pub fn alloc_slice_clone<T: Clone>(&self, slice: &[T]) -> BumpBox<'a, [T]>

Allocate a slice and fill it by Cloneing elements from an existing slice.

Panics

Panics if the allocation fails.

Examples

let allocated = bump.alloc_slice_clone(&[String::from("a"), String::from("b")]);
assert_eq!(allocated, [String::from("a"), String::from("b")]);

pub fn try_alloc_slice_clone<T: Clone>( &self, slice: &[T], ) -> Result<BumpBox<'a, [T]>, AllocError>

Allocate a slice and fill it by Cloneing elements from an existing slice.

Errors

Errors if the allocation fails.

Examples

let allocated = bump.try_alloc_slice_clone(&[String::from("a"), String::from("b")])?;
assert_eq!(allocated, [String::from("a"), String::from("b")]);

pub fn alloc_slice_fill<T: Clone>( &self, len: usize, value: T, ) -> BumpBox<'a, [T]>

Allocate a slice and fill it with elements by cloning value.

Panics

Panics if the allocation fails.

Examples

let allocated = bump.alloc_slice_fill(3, "ho");
assert_eq!(allocated, ["ho", "ho", "ho"]);

pub fn try_alloc_slice_fill<T: Clone>( &self, len: usize, value: T, ) -> Result<BumpBox<'a, [T]>, AllocError>

Allocate a slice and fill it with elements by cloning value.

Errors

Errors if the allocation fails.

Examples

let allocated = bump.try_alloc_slice_fill(3, "ho")?;
assert_eq!(allocated, ["ho", "ho", "ho"]);

pub fn alloc_slice_fill_with<T>( &self, len: usize, f: impl FnMut() -> T, ) -> BumpBox<'a, [T]>

Allocates a slice by fill it with elements returned by calling a closure repeatedly.

This method uses a closure to create new values. If you’d rather Clone a given value, use alloc_slice_fill. If you want to use the Default trait to generate values, you can pass Default::default as the argument.

Panics

Panics if the allocation fails.

Examples

let allocated = bump.alloc_slice_fill_with::<i32>(3, Default::default);
assert_eq!(allocated, [0, 0, 0]);

pub fn try_alloc_slice_fill_with<T>( &self, len: usize, f: impl FnMut() -> T, ) -> Result<BumpBox<'a, [T]>, AllocError>

Allocates a slice by fill it with elements returned by calling a closure repeatedly.

This method uses a closure to create new values. If you’d rather Clone a given value, use try_alloc_slice_fill. If you want to use the Default trait to generate values, you can pass Default::default as the argument.

Errors

Errors if the allocation fails.

Examples

let allocated = bump.try_alloc_slice_fill_with::<i32>(3, Default::default)?;
assert_eq!(allocated, [0, 0, 0]);

pub fn alloc_str(&self, src: &str) -> BumpBox<'a, str>

Allocate a str.

Panics

Panics if the allocation fails.

Examples

let allocated = bump.alloc_str("Hello, world!");
assert_eq!(allocated, "Hello, world!");

pub fn try_alloc_str(&self, src: &str) -> Result<BumpBox<'a, str>, AllocError>

Allocate a str.

Errors

Errors if the allocation fails.

Examples

let allocated = bump.try_alloc_str("Hello, world!")?;
assert_eq!(allocated, "Hello, world!");

pub fn alloc_fmt(&self, args: Arguments<'_>) -> BumpBox<'a, str>

Allocate a str from format arguments.

If you have a &mut self you can use alloc_fmt_mut instead for better performance.

Panics

Panics if the allocation fails.

This technically also panics if the fmt() implementation returned an Error, but since fmt() implementors should only error when writing to the stream fails, that should be equivalent to an allocation failure.

Examples

let one = 1;
let two = 2;
let string = bump.alloc_fmt(format_args!("{one} + {two} = {}", one + two));

assert_eq!(string, "1 + 2 = 3");

pub fn try_alloc_fmt( &self, args: Arguments<'_>, ) -> Result<BumpBox<'a, str>, AllocError>

Allocate a str from format arguments.

If you have a &mut self you can use try_alloc_fmt_mut instead for better performance.

Errors

Errors if the allocation fails.

This technically also errors if the fmt() implementation returned an Error, but since fmt() implementors should only error when writing to the stream fails, that should be equivalent to an allocation failure.

Examples

let one = 1;
let two = 2;
let string = bump.try_alloc_fmt(format_args!("{one} + {two} = {}", one + two))?;

assert_eq!(string, "1 + 2 = 3");

pub fn alloc_fmt_mut(&mut self, args: Arguments<'_>) -> BumpBox<'a, str>

Allocate a str from format arguments.

This function is designed as a performance improvement over alloc_fmt. By taking self as &mut, it can use the entire remaining chunk space as the capacity for the temporary string buffer used for the allocation. As a result, that string buffer rarely needs to grow.

Panics

Panics if the allocation fails.

This technically also panics if the fmt() implementation returned an Error, but since fmt() implementors should only error when writing to the stream fails, that should be equivalent to an allocation failure.

Examples

let one = 1;
let two = 2;
let string = bump.alloc_fmt_mut(format_args!("{one} + {two} = {}", one + two));

assert_eq!(string, "1 + 2 = 3");

pub fn try_alloc_fmt_mut( &mut self, args: Arguments<'_>, ) -> Result<BumpBox<'a, str>, AllocError>

Allocate a str from format arguments.

This function is designed as a performance improvement over try_alloc_fmt. By taking self as &mut, it can use the entire remaining chunk space as the capacity for the temporary string buffer used for the allocation. As a result, that string buffer rarely needs to grow.

Errors

Errors if the allocation fails.

This technically also errors if the fmt() implementation returned an Error, but since fmt() implementors should only error when writing to the stream fails, that should be equivalent to an allocation failure.

Examples

let one = 1;
let two = 2;
let string = bump.try_alloc_fmt_mut(format_args!("{one} + {two} = {}", one + two))?;

assert_eq!(string, "1 + 2 = 3");

pub fn alloc_cstr(&self, src: &CStr) -> &'a CStr

Allocate a CStr.

Panics

Panics if the allocation fails.

Examples

let allocated = bump.alloc_cstr(c"Hello, world!");
assert_eq!(allocated, c"Hello, world!");

pub fn try_alloc_cstr(&self, src: &CStr) -> Result<&'a CStr, AllocError>

Allocate a CStr.

Errors

Errors if the allocation fails.

Examples

let allocated = bump.try_alloc_cstr(c"Hello, world!")?;
assert_eq!(allocated, c"Hello, world!");

pub fn alloc_cstr_from_str(&self, src: &str) -> &'a CStr

Allocate a CStr from a str.

If src contains a '\0' then the CStr will stop at the first '\0'.

Panics

Panics if the allocation fails.

Examples

let allocated = bump.alloc_cstr_from_str("Hello, world!");
assert_eq!(allocated, c"Hello, world!");

let allocated = bump.alloc_cstr_from_str("abc\0def");
assert_eq!(allocated, c"abc");

pub fn try_alloc_cstr_from_str(&self, src: &str) -> Result<&'a CStr, AllocError>

Allocate a CStr from a str.

If src contains a '\0' then the CStr will stop at the first '\0'.

Errors

Errors if the allocation fails.

Examples

let allocated = bump.try_alloc_cstr_from_str("Hello, world!")?;
assert_eq!(allocated, c"Hello, world!");

let allocated = bump.try_alloc_cstr_from_str("abc\0def")?;
assert_eq!(allocated, c"abc");

pub fn alloc_cstr_fmt(&self, args: Arguments<'_>) -> &'a CStr

Allocate a CStr from format arguments.

If the string contains a '\0' then the CStr will stop at the first '\0'.

If you have a &mut self you can use alloc_cstr_fmt_mut instead for better performance.

Panics

Panics if the allocation fails.

This technically also panics if the fmt() implementation returned an Error, but since fmt() implementors should only error when writing to the stream fails, that should be equivalent to an allocation failure.

Examples

let one = 1;
let two = 2;
let string = bump.alloc_cstr_fmt(format_args!("{one} + {two} = {}", one + two));
assert_eq!(string, c"1 + 2 = 3");

let one = bump.alloc_cstr_fmt(format_args!("{one}\0{two}"));
assert_eq!(one, c"1");

pub fn try_alloc_cstr_fmt( &self, args: Arguments<'_>, ) -> Result<&'a CStr, AllocError>

Allocate a CStr from format arguments.

If the string contains a '\0' then the CStr will stop at the first '\0'.

If you have a &mut self you can use try_alloc_cstr_fmt_mut instead for better performance.

Errors

Errors if the allocation fails.

This technically also errors if the fmt() implementation returned an Error, but since fmt() implementors should only error when writing to the stream fails, that should be equivalent to an allocation failure.

Examples

let one = 1;
let two = 2;
let string = bump.try_alloc_cstr_fmt(format_args!("{one} + {two} = {}", one + two))?;
assert_eq!(string, c"1 + 2 = 3");

let one = bump.try_alloc_cstr_fmt(format_args!("{one}\0{two}"))?;
assert_eq!(one, c"1");

pub fn alloc_cstr_fmt_mut(&mut self, args: Arguments<'_>) -> &'a CStr

Allocate a CStr from format arguments.

If the string contains a '\0' then the CStr will stop at the first '\0'.

This function is designed as a performance improvement over alloc_cstr_fmt. By taking self as &mut, it can use the entire remaining chunk space as the capacity for the temporary string buffer used for the allocation. As a result, that string buffer rarely needs to grow.

Panics

Panics if the allocation fails.

This technically also panics if the fmt() implementation returned an Error, but since fmt() implementors should only error when writing to the stream fails, that should be equivalent to an allocation failure.

Examples

let one = 1;
let two = 2;
let string = bump.alloc_cstr_fmt_mut(format_args!("{one} + {two} = {}", one + two));
assert_eq!(string, c"1 + 2 = 3");

let one = bump.alloc_cstr_fmt_mut(format_args!("{one}\0{two}"));
assert_eq!(one, c"1");

pub fn try_alloc_cstr_fmt_mut( &mut self, args: Arguments<'_>, ) -> Result<&'a CStr, AllocError>

Allocate a CStr from format arguments.

If the string contains a '\0' then the CStr will stop at the first '\0'.

This function is designed as a performance improvement over try_alloc_cstr_fmt. By taking self as &mut, it can use the entire remaining chunk space as the capacity for the temporary string buffer used for the allocation. As a result, that string buffer rarely needs to grow.

Errors

Errors if the allocation fails.

This technically also errors if the fmt() implementation returned an Error, but since fmt() implementors should only error when writing to the stream fails, that should be equivalent to an allocation failure.

Examples

let one = 1;
let two = 2;
let string = bump.try_alloc_cstr_fmt_mut(format_args!("{one} + {two} = {}", one + two))?;
assert_eq!(string, c"1 + 2 = 3");

let one = bump.try_alloc_cstr_fmt_mut(format_args!("{one}\0{two}"))?;
assert_eq!(one, c"1");

pub fn alloc_iter<T>( &self, iter: impl IntoIterator<Item = T>, ) -> BumpBox<'a, [T]>

Allocate elements of an iterator into a slice.

If you have an impl ExactSizeIterator then you can use alloc_iter_exact instead for better performance.

If iter is not an ExactSizeIterator but you have a &mut self you can still get somewhat better performance by using alloc_iter_mut.

Panics

Panics if the allocation fails.

Examples

let slice = bump.alloc_iter([1, 2, 3]);
assert_eq!(slice, [1, 2, 3]);

pub fn try_alloc_iter<T>( &self, iter: impl IntoIterator<Item = T>, ) -> Result<BumpBox<'a, [T]>, AllocError>

Allocate elements of an iterator into a slice.

If you have an impl ExactSizeIterator then you can use try_alloc_iter_exact instead for better performance.

If iter is not an ExactSizeIterator but you have a &mut self you can still get somewhat better performance by using try_alloc_iter_mut.

Errors

Errors if the allocation fails.

Examples

let slice = bump.try_alloc_iter([1, 2, 3])?;
assert_eq!(slice, [1, 2, 3]);

pub fn alloc_iter_exact<T, I>( &self, iter: impl IntoIterator<Item = T, IntoIter = I>, ) -> BumpBox<'a, [T]>

where I: ExactSizeIterator<Item = T>,

Allocate elements of an ExactSizeIterator into a slice.

Panics

Panics if the allocation fails.

Examples

let slice = bump.alloc_iter_exact([1, 2, 3]);
assert_eq!(slice, [1, 2, 3]);

pub fn try_alloc_iter_exact<T, I>( &self, iter: impl IntoIterator<Item = T, IntoIter = I>, ) -> Result<BumpBox<'a, [T]>, AllocError>

where I: ExactSizeIterator<Item = T>,

Allocate elements of an ExactSizeIterator into a slice.

Errors

Errors if the allocation fails.

Examples

let slice = bump.try_alloc_iter_exact([1, 2, 3])?;
assert_eq!(slice, [1, 2, 3]);

pub fn alloc_iter_mut<T>( &mut self, iter: impl IntoIterator<Item = T>, ) -> BumpBox<'a, [T]>

Allocate elements of an iterator into a slice.

This function is designed as a performance improvement over alloc_iter. By taking self as &mut, it can use the entire remaining chunk space as the capacity for the temporary vector used for the allocation. As a result, that vector rarely needs to grow.

When bumping downwards, prefer alloc_iter_mut_rev instead.

Panics

Panics if the allocation fails.

Examples

let slice = bump.alloc_iter_mut([1, 2, 3]);
assert_eq!(slice, [1, 2, 3]);

pub fn try_alloc_iter_mut<T>( &mut self, iter: impl IntoIterator<Item = T>, ) -> Result<BumpBox<'a, [T]>, AllocError>

Allocate elements of an iterator into a slice.

This function is designed as a performance improvement over try_alloc_iter. By taking self as &mut, it can use the entire remaining chunk space as the capacity for the temporary vector used for the allocation. As a result, that vector rarely needs to grow.

When bumping downwards, prefer alloc_iter_mut_rev instead.

Errors

Errors if the allocation fails.

Examples

let slice = bump.try_alloc_iter_mut([1, 2, 3])?;
assert_eq!(slice, [1, 2, 3]);

pub fn alloc_iter_mut_rev<T>( &mut self, iter: impl IntoIterator<Item = T>, ) -> BumpBox<'a, [T]>

Allocate elements of an iterator into a slice in reverse order.

Compared to alloc_iter_mut this function is more performant for downwards bumping allocators as the allocation for the vector can be shrunk in place without any ptr::copy.

The reverse is true when upwards allocating. In that case it’s better to use alloc_iter_mut to prevent the ptr::copy.

Panics

Panics if the allocation fails.

Examples

let slice = bump.alloc_iter_mut_rev([1, 2, 3]);
assert_eq!(slice, [3, 2, 1]);

pub fn try_alloc_iter_mut_rev<T>( &mut self, iter: impl IntoIterator<Item = T>, ) -> Result<BumpBox<'a, [T]>, AllocError>

Allocate elements of an iterator into a slice in reverse order.

Compared to try_alloc_iter_mut this function is more performant for downwards bumping allocators as the allocation for the vector can be shrunk in place without any ptr::copy.

The reverse is true when upwards allocating. In that case it’s better to use try_alloc_iter_mut to prevent the ptr::copy.

Errors

Errors if the allocation fails.

Examples

let slice = bump.try_alloc_iter_mut_rev([1, 2, 3])?;
assert_eq!(slice, [3, 2, 1]);

pub fn alloc_uninit<T>(&self) -> BumpBox<'a, MaybeUninit<T>>

Allocate an unitialized object.

You can safely initialize the object with init or unsafely with assume_init.

Panics

Panics if the allocation fails.

Examples

Safely:

let uninit = bump.alloc_uninit();

let five = uninit.init(5);

assert_eq!(*five, 5)

Unsafely:

let mut uninit = bump.alloc_uninit();

let five = unsafe {
    uninit.write(5);
    uninit.assume_init()
};

assert_eq!(*five, 5)

pub fn try_alloc_uninit<T>( &self, ) -> Result<BumpBox<'a, MaybeUninit<T>>, AllocError>

Allocate an unitialized object.

You can safely initialize the object with init or unsafely with assume_init.

Errors

Errors if the allocation fails.

Examples

Safely:

let uninit = bump.try_alloc_uninit()?;

let five = uninit.init(5);

assert_eq!(*five, 5);

Unsafely:

let mut uninit = bump.try_alloc_uninit()?;

let five = unsafe {
    uninit.write(5);
    uninit.assume_init()
};

assert_eq!(*five, 5);

pub fn alloc_uninit_slice<T>(&self, len: usize) -> BumpBox<'a, [MaybeUninit<T>]>

Allocate an unitialized object slice.

You can safely initialize the object with init_fill, init_fill_with, init_copy, init_clone, init_zeroed or unsafely with assume_init.

Panics

Panics if the allocation fails.

Examples

Safely:

let uninit = bump.alloc_uninit_slice(3);

let values = uninit.init_copy(&[1, 2, 3]);

assert_eq!(values, [1, 2, 3])

Unsafely:

let mut uninit = bump.alloc_uninit_slice(3);

let values = unsafe {
    uninit[0].write(1);
    uninit[1].write(2);
    uninit[2].write(3);

    uninit.assume_init()
};

assert_eq!(values, [1, 2, 3]);

pub fn try_alloc_uninit_slice<T>( &self, len: usize, ) -> Result<BumpBox<'a, [MaybeUninit<T>]>, AllocError>

Allocate an unitialized object slice.

You can safely initialize the object with init_fill, init_fill_with, init_copy, init_clone, init_zeroed or unsafely with assume_init.

Errors

Errors if the allocation fails.

Examples

Safely:

let uninit = bump.try_alloc_uninit_slice(3)?;

let values = uninit.init_copy(&[1, 2, 3]);

assert_eq!(values, [1, 2, 3]);

Unsafely:

let mut uninit = bump.try_alloc_uninit_slice(3)?;

let values = unsafe {
    uninit[0].write(1);
    uninit[1].write(2);
    uninit[2].write(3);

    uninit.assume_init()
};

assert_eq!(values, [1, 2, 3]);

pub fn alloc_uninit_slice_for<T>( &self, slice: &[T], ) -> BumpBox<'a, [MaybeUninit<T>]>

Allocate an unitialized object slice.

You can safely initialize the object with init_fill, init_fill_with, init_copy, init_clone, init_zeroed or unsafely with assume_init.

This is just like alloc_uninit_slice but uses a slice to provide the len. This avoids a check for a valid layout. The elements of slice are irrelevant.

Panics

Panics if the allocation fails.

Examples

let slice = &[1, 2, 3];
let uninit_slice = bump.alloc_uninit_slice_for(slice);
assert_eq!(uninit_slice.len(), 3);

pub fn try_alloc_uninit_slice_for<T>( &self, slice: &[T], ) -> Result<BumpBox<'a, [MaybeUninit<T>]>, AllocError>

Allocate an unitialized object slice.

You can safely initialize the object with init_fill, init_fill_with, init_copy, init_clone, init_zeroed or unsafely with assume_init.

This is just like try_alloc_uninit_slice but uses a slice to provide the len. This avoids a check for a valid layout. The elements of slice are irrelevant.

Errors

Errors if the allocation fails.

Examples

let slice = &[1, 2, 3];
let uninit_slice = bump.try_alloc_uninit_slice_for(slice)?;
assert_eq!(uninit_slice.len(), 3);

pub fn alloc_layout(&self, layout: Layout) -> NonNull<u8>

Allocates memory as described by the given Layout.

Panics

Panics if the allocation fails.

pub fn try_alloc_layout( &self, layout: Layout, ) -> Result<NonNull<u8>, AllocError>

Allocates memory as described by the given Layout.

Errors

Errors if the allocation fails.

pub fn dealloc<T: ?Sized>(&self, boxed: BumpBox<'_, T>)

Drops an allocated value and attempts to free its memory.

The memory can only be freed if this is the last allocation.

Examples

let boxed = bump.alloc(3i32);
assert_eq!(bump.stats().allocated(), 4);
bump.dealloc(boxed);
assert_eq!(bump.stats().allocated(), 0);

pub fn reserve_bytes(&self, additional: usize)

Reserves capacity for at least additional more bytes to be bump allocated. The bump allocator may reserve more space to avoid frequent reallocations. After calling reserve_bytes, self.stats().remaining() will be greater than or equal to additional. Does nothing if the capacity is already sufficient.

Note that these additional bytes are not necessarily in one contiguous region but might be spread out among many chunks.

Panics

Panics if the allocation fails.

Examples

let bump: Bump = Bump::new();
assert!(bump.stats().capacity() < 4096);

bump.reserve_bytes(4096);
assert!(bump.stats().capacity() >= 4096);

pub fn try_reserve_bytes(&self, additional: usize) -> Result<(), AllocError>

Reserves capacity for at least additional more bytes to be bump allocated. The bump allocator may reserve more space to avoid frequent reallocations. After calling reserve_bytes, self.stats().remaining() will be greater than or equal to additional. Does nothing if the capacity is already sufficient.

Errors

Errors if the allocation fails.

Examples

let bump: Bump = Bump::try_new()?;
assert!(bump.stats().capacity() < 4096);

bump.try_reserve_bytes(4096)?;
assert!(bump.stats().capacity() >= 4096);

pub fn alloc_try_with<T, E>( &self, f: impl FnOnce() -> Result<T, E>, ) -> Result<BumpBox<'a, T>, E>

Allocates the result of f in the bump allocator, then moves E out of it and deallocates the space it took up.

This can be more performant than allocating T after the fact, as Result<T, E> may be constructed in the bump allocators memory instead of on the stack and then copied over.

There is also alloc_try_with_mut, optimized for a mutable reference.

Panics

Panics if the allocation fails.

Examples

let result = bump.alloc_try_with(|| -> Result<i32, i32> { Ok(123) });
assert_eq!(result.unwrap(), 123);
assert_eq!(bump.stats().allocated(), offset_of!(Result<i32, i32>, Ok.0) + size_of::<i32>());

let result = bump.alloc_try_with(|| -> Result<i32, i32> { Err(123) });
assert_eq!(result.unwrap_err(), 123);
assert_eq!(bump.stats().allocated(), 0);

pub fn try_alloc_try_with<T, E>( &self, f: impl FnOnce() -> Result<T, E>, ) -> Result<Result<BumpBox<'a, T>, E>, AllocError>

Allocates the result of f in the bump allocator, then moves E out of it and deallocates the space it took up.

This can be more performant than allocating T after the fact, as Result<T, E> may be constructed in the bump allocators memory instead of on the stack and then copied over.

There is also try_alloc_try_with_mut, optimized for a mutable reference.

Errors

Errors if the allocation fails.

Examples

let result = bump.try_alloc_try_with(|| -> Result<i32, i32> { Ok(123) })?;
assert_eq!(result.unwrap(), 123);
assert_eq!(bump.stats().allocated(), offset_of!(Result<i32, i32>, Ok.0) + size_of::<i32>());

let result = bump.try_alloc_try_with(|| -> Result<i32, i32> { Err(123) })?;
assert_eq!(result.unwrap_err(), 123);
assert_eq!(bump.stats().allocated(), 0);

pub fn alloc_try_with_mut<T, E>( &mut self, f: impl FnOnce() -> Result<T, E>, ) -> Result<BumpBox<'a, T>, E>

Allocates the result of f in the bump allocator, then moves E out of it and deallocates the space it took up.

This can be more performant than allocating T after the fact, as Result<T, E> may be constructed in the bump allocators memory instead of on the stack and then copied over.

This is just like alloc_try_with, but optimized for a mutable reference.

Panics

Panics if the allocation fails.

Examples

let result = bump.alloc_try_with_mut(|| -> Result<i32, i32> { Ok(123) });
assert_eq!(result.unwrap(), 123);
assert_eq!(bump.stats().allocated(), offset_of!(Result<i32, i32>, Ok.0) + size_of::<i32>());

let result = bump.alloc_try_with_mut(|| -> Result<i32, i32> { Err(123) });
assert_eq!(result.unwrap_err(), 123);
assert_eq!(bump.stats().allocated(), 0);

pub fn try_alloc_try_with_mut<T, E>( &mut self, f: impl FnOnce() -> Result<T, E>, ) -> Result<Result<BumpBox<'a, T>, E>, AllocError>

Allocates the result of f in the bump allocator, then moves E out of it and deallocates the space it took up.

This can be more performant than allocating T after the fact, as Result<T, E> may be constructed in the bump allocators memory instead of on the stack and then copied over.

This is just like try_alloc_try_with, but optimized for a mutable reference.

Errors

Errors if the allocation fails.

Examples

let result = bump.try_alloc_try_with_mut(|| -> Result<i32, i32> { Ok(123) })?;
assert_eq!(result.unwrap(), 123);
assert_eq!(bump.stats().allocated(), offset_of!(Result<i32, i32>, Ok.0) + size_of::<i32>());

let result = bump.try_alloc_try_with_mut(|| -> Result<i32, i32> { Err(123) })?;
assert_eq!(result.unwrap_err(), 123);
assert_eq!(bump.stats().allocated(), 0);

Trait Implementations

impl<A, const MIN_ALIGN: usize, const UP: bool, const GUARANTEED_ALLOCATED: bool, const DEALLOCATES: bool> Allocator for &mut BumpScope<'_, A, MIN_ALIGN, UP, GUARANTEED_ALLOCATED, DEALLOCATES>

where MinimumAlignment<MIN_ALIGN>: SupportedMinimumAlignment, A: BaseAllocator<GUARANTEED_ALLOCATED>,

Available on crate feature nightly-allocator-api only.

fn allocate(&self, layout: Layout) -> Result<NonNull<[u8]>, AllocError>

🔬This is a nightly-only experimental API. (allocator_api)

Attempts to allocate a block of memory.

unsafe fn deallocate(&self, ptr: NonNull<u8>, layout: Layout)

🔬This is a nightly-only experimental API. (allocator_api)

Deallocates the memory referenced by ptr.

unsafe fn grow( &self, ptr: NonNull<u8>, old_layout: Layout, new_layout: Layout, ) -> Result<NonNull<[u8]>, AllocError>

🔬This is a nightly-only experimental API. (allocator_api)

Attempts to extend the memory block.

unsafe fn grow_zeroed( &self, ptr: NonNull<u8>, old_layout: Layout, new_layout: Layout, ) -> Result<NonNull<[u8]>, AllocError>

🔬This is a nightly-only experimental API. (allocator_api)

Behaves like grow, but also ensures that the new contents are set to zero before being returned.

unsafe fn shrink( &self, ptr: NonNull<u8>, old_layout: Layout, new_layout: Layout, ) -> Result<NonNull<[u8]>, AllocError>

🔬This is a nightly-only experimental API. (allocator_api)

Attempts to shrink the memory block.

fn allocate_zeroed(&self, layout: Layout) -> Result<NonNull<[u8]>, AllocError>

🔬This is a nightly-only experimental API. (allocator_api)

Behaves like allocate, but also ensures that the returned memory is zero-initialized.

fn by_ref(&self) -> &Self

where Self: Sized,

🔬This is a nightly-only experimental API. (allocator_api)

Creates a “by reference” adapter for this instance of Allocator.

impl<A, const MIN_ALIGN: usize, const UP: bool, const GUARANTEED_ALLOCATED: bool, const DEALLOCATES: bool> Allocator for &mut BumpScope<'_, A, MIN_ALIGN, UP, GUARANTEED_ALLOCATED, DEALLOCATES>

where MinimumAlignment<MIN_ALIGN>: SupportedMinimumAlignment, A: BaseAllocator<GUARANTEED_ALLOCATED>,

Available on crate feature allocator-api2-03 only.

fn allocate(&self, layout: Layout) -> Result<NonNull<[u8]>, AllocError>

Attempts to allocate a block of memory.

unsafe fn deallocate(&self, ptr: NonNull<u8>, layout: Layout)

Deallocates the memory referenced by ptr.

unsafe fn grow( &self, ptr: NonNull<u8>, old_layout: Layout, new_layout: Layout, ) -> Result<NonNull<[u8]>, AllocError>

Attempts to extend the memory block.

unsafe fn grow_zeroed( &self, ptr: NonNull<u8>, old_layout: Layout, new_layout: Layout, ) -> Result<NonNull<[u8]>, AllocError>

Behaves like grow, but also ensures that the new contents are set to zero before being returned.

unsafe fn shrink( &self, ptr: NonNull<u8>, old_layout: Layout, new_layout: Layout, ) -> Result<NonNull<[u8]>, AllocError>

Attempts to shrink the memory block.

fn allocate_zeroed(&self, layout: Layout) -> Result<NonNull<[u8]>, AllocError>

Behaves like allocate, but also ensures that the returned memory is zero-initialized.

fn by_ref(&self) -> &Self

where Self: Sized,

Creates a “by reference” adapter for this instance of Allocator.

impl<A, const MIN_ALIGN: usize, const UP: bool, const GUARANTEED_ALLOCATED: bool, const DEALLOCATES: bool> Allocator for BumpScope<'_, A, MIN_ALIGN, UP, GUARANTEED_ALLOCATED, DEALLOCATES>

where MinimumAlignment<MIN_ALIGN>: SupportedMinimumAlignment, A: BaseAllocator<GUARANTEED_ALLOCATED>,

fn allocate(&self, layout: Layout) -> Result<NonNull<[u8]>, AllocError>

Attempts to allocate a block of memory.

unsafe fn deallocate(&self, ptr: NonNull<u8>, layout: Layout)

Deallocates the memory referenced by ptr.

unsafe fn grow( &self, ptr: NonNull<u8>, old_layout: Layout, new_layout: Layout, ) -> Result<NonNull<[u8]>, AllocError>

Attempts to extend the memory block.

unsafe fn grow_zeroed( &self, ptr: NonNull<u8>, old_layout: Layout, new_layout: Layout, ) -> Result<NonNull<[u8]>, AllocError>

Behaves like grow, but also ensures that the new contents are set to zero before being returned.

unsafe fn shrink( &self, ptr: NonNull<u8>, old_layout: Layout, new_layout: Layout, ) -> Result<NonNull<[u8]>, AllocError>

Attempts to shrink the memory block.

fn allocate_zeroed(&self, layout: Layout) -> Result<NonNull<[u8]>, AllocError>

Behaves like allocate, but also ensures that the returned memory is zero-initialized.

fn by_ref(&self) -> &Self

where Self: Sized,

Creates a “by reference” adapter for this instance of Allocator.

impl<A, const MIN_ALIGN: usize, const UP: bool, const GUARANTEED_ALLOCATED: bool, const DEALLOCATES: bool> Allocator for BumpScope<'_, A, MIN_ALIGN, UP, GUARANTEED_ALLOCATED, DEALLOCATES>

where MinimumAlignment<MIN_ALIGN>: SupportedMinimumAlignment, A: BaseAllocator<GUARANTEED_ALLOCATED>,

Available on crate feature nightly-allocator-api only.

fn allocate(&self, layout: Layout) -> Result<NonNull<[u8]>, AllocError>

🔬This is a nightly-only experimental API. (allocator_api)

Attempts to allocate a block of memory.

unsafe fn deallocate(&self, ptr: NonNull<u8>, layout: Layout)

🔬This is a nightly-only experimental API. (allocator_api)

Deallocates the memory referenced by ptr.

unsafe fn grow( &self, ptr: NonNull<u8>, old_layout: Layout, new_layout: Layout, ) -> Result<NonNull<[u8]>, AllocError>

🔬This is a nightly-only experimental API. (allocator_api)

Attempts to extend the memory block.

unsafe fn grow_zeroed( &self, ptr: NonNull<u8>, old_layout: Layout, new_layout: Layout, ) -> Result<NonNull<[u8]>, AllocError>

🔬This is a nightly-only experimental API. (allocator_api)

Behaves like grow, but also ensures that the new contents are set to zero before being returned.

unsafe fn shrink( &self, ptr: NonNull<u8>, old_layout: Layout, new_layout: Layout, ) -> Result<NonNull<[u8]>, AllocError>

🔬This is a nightly-only experimental API. (allocator_api)

Attempts to shrink the memory block.

fn allocate_zeroed(&self, layout: Layout) -> Result<NonNull<[u8]>, AllocError>

🔬This is a nightly-only experimental API. (allocator_api)

Behaves like allocate, but also ensures that the returned memory is zero-initialized.

fn by_ref(&self) -> &Self

where Self: Sized,

🔬This is a nightly-only experimental API. (allocator_api)

Creates a “by reference” adapter for this instance of Allocator.

impl<A, const MIN_ALIGN: usize, const UP: bool, const GUARANTEED_ALLOCATED: bool, const DEALLOCATES: bool> Allocator for BumpScope<'_, A, MIN_ALIGN, UP, GUARANTEED_ALLOCATED, DEALLOCATES>

where MinimumAlignment<MIN_ALIGN>: SupportedMinimumAlignment, A: BaseAllocator<GUARANTEED_ALLOCATED>,

Available on crate feature allocator-api2-03 only.

fn allocate(&self, layout: Layout) -> Result<NonNull<[u8]>, AllocError>

Attempts to allocate a block of memory.

unsafe fn deallocate(&self, ptr: NonNull<u8>, layout: Layout)

Deallocates the memory referenced by ptr.

unsafe fn grow( &self, ptr: NonNull<u8>, old_layout: Layout, new_layout: Layout, ) -> Result<NonNull<[u8]>, AllocError>

Attempts to extend the memory block.

unsafe fn grow_zeroed( &self, ptr: NonNull<u8>, old_layout: Layout, new_layout: Layout, ) -> Result<NonNull<[u8]>, AllocError>

Behaves like grow, but also ensures that the new contents are set to zero before being returned.

unsafe fn shrink( &self, ptr: NonNull<u8>, old_layout: Layout, new_layout: Layout, ) -> Result<NonNull<[u8]>, AllocError>

Attempts to shrink the memory block.

fn allocate_zeroed(&self, layout: Layout) -> Result<NonNull<[u8]>, AllocError>

Behaves like allocate, but also ensures that the returned memory is zero-initialized.

fn by_ref(&self) -> &Self

where Self: Sized,

Creates a “by reference” adapter for this instance of Allocator.

impl<A, const MIN_ALIGN: usize, const UP: bool, const GUARANTEED_ALLOCATED: bool, const DEALLOCATES: bool> BumpAllocator for BumpScope<'_, A, MIN_ALIGN, UP, GUARANTEED_ALLOCATED, DEALLOCATES>

where MinimumAlignment<MIN_ALIGN>: SupportedMinimumAlignment, A: BaseAllocator<GUARANTEED_ALLOCATED>,

fn any_stats(&self) -> AnyStats<'_>

Returns a type which provides statistics about the memory usage of the bump allocator.

fn checkpoint(&self) -> Checkpoint

Creates a checkpoint of the current bump position.

unsafe fn reset_to(&self, checkpoint: Checkpoint)

Resets the bump position to a previously created checkpoint. The memory that has been allocated since then will be reused by future allocations.

fn prepare_allocation( &self, layout: Layout, ) -> Result<Range<NonNull<u8>>, AllocError>

Returns a pointer range of free space in the bump allocator with a size of at least layout.size().

unsafe fn allocate_prepared( &self, layout: Layout, range: Range<NonNull<u8>>, ) -> NonNull<u8>

Allocate part of the free space returned from a prepare_allocation call.

unsafe fn allocate_prepared_rev( &self, layout: Layout, range: Range<NonNull<u8>>, ) -> NonNull<u8>

Allocate part of the free space returned from a prepare_allocation call starting at the end.

impl<A, const MIN_ALIGN: usize, const UP: bool, const GUARANTEED_ALLOCATED: bool, const DEALLOCATES: bool> BumpAllocatorExt for BumpScope<'_, A, MIN_ALIGN, UP, GUARANTEED_ALLOCATED, DEALLOCATES>

where MinimumAlignment<MIN_ALIGN>: SupportedMinimumAlignment, A: BaseAllocator<GUARANTEED_ALLOCATED>,

type Stats<'b> = Stats<'b, A, UP, GUARANTEED_ALLOCATED> where Self: 'b

The type returned by the stats method.

fn stats(&self) -> Self::Stats<'_>

Returns a type which provides statistics about the memory usage of the bump allocator.

fn allocate_layout(&self, layout: Layout) -> NonNull<u8>

A specialized version of allocate.

fn try_allocate_layout(&self, layout: Layout) -> Result<NonNull<u8>, AllocError>

A specialized version of allocate.

fn allocate_sized<T>(&self) -> NonNull<T>

A specialized version of allocate.

fn try_allocate_sized<T>(&self) -> Result<NonNull<T>, AllocError>

A specialized version of allocate.

fn allocate_slice<T>(&self, len: usize) -> NonNull<T>

A specialized version of allocate.

fn try_allocate_slice<T>(&self, len: usize) -> Result<NonNull<T>, AllocError>

A specialized version of allocate.

unsafe fn shrink_slice<T>( &self, ptr: NonNull<T>, old_len: usize, new_len: usize, ) -> Option<NonNull<T>>

A specialized version of shrink.

fn prepare_slice_allocation<T>(&self, len: usize) -> NonNull<[T]>

A specialized version of prepare_allocation.

fn try_prepare_slice_allocation<T>( &self, len: usize, ) -> Result<NonNull<[T]>, AllocError>

A specialized version of prepare_allocation.

unsafe fn allocate_prepared_slice<T>( &self, ptr: NonNull<T>, len: usize, cap: usize, ) -> NonNull<[T]>

A specialized version of allocate_prepared.

unsafe fn allocate_prepared_slice_rev<T>( &self, ptr: NonNull<T>, len: usize, cap: usize, ) -> NonNull<[T]>

A specialized version of allocate_prepared_rev.

impl<'a, A, const MIN_ALIGN: usize, const UP: bool, const GUARANTEED_ALLOCATED: bool, const DEALLOCATES: bool> BumpScopeExt<'a> for BumpScope<'a, A, MIN_ALIGN, UP, GUARANTEED_ALLOCATED, DEALLOCATES>

where MinimumAlignment<MIN_ALIGN>: SupportedMinimumAlignment, A: BaseAllocator<GUARANTEED_ALLOCATED>,

Available on crate feature bytemuck only.

fn alloc_zeroed<T>(&self) -> BumpBox<'a, T>

where T: Zeroable,

Allocate a zeroed object.

fn try_alloc_zeroed<T>(&self) -> Result<BumpBox<'a, T>, AllocError>

where T: Zeroable,

Allocate a zeroed object.

fn alloc_zeroed_slice<T>(&self, len: usize) -> BumpBox<'a, [T]>

where T: Zeroable,

Allocate a zeroed object slice.

fn try_alloc_zeroed_slice<T>( &self, len: usize, ) -> Result<BumpBox<'a, [T]>, AllocError>

where T: Zeroable,

Allocate a zeroed object slice.

impl<'a, A, const MIN_ALIGN: usize, const UP: bool, const GUARANTEED_ALLOCATED: bool, const DEALLOCATES: bool> BumpScopeExt<'a> for BumpScope<'a, A, MIN_ALIGN, UP, GUARANTEED_ALLOCATED, DEALLOCATES>

where MinimumAlignment<MIN_ALIGN>: SupportedMinimumAlignment, A: BaseAllocator<GUARANTEED_ALLOCATED>,

Available on crate feature zerocopy-08 only.

fn alloc_zeroed<T>(&self) -> BumpBox<'a, T>

where T: FromZeros,

Allocate a zeroed object.

fn try_alloc_zeroed<T>(&self) -> Result<BumpBox<'a, T>, AllocError>

where T: FromZeros,

Allocate a zeroed object.

fn alloc_zeroed_slice<T>(&self, len: usize) -> BumpBox<'a, [T]>

where T: FromZeros,

Allocate a zeroed object slice.

fn try_alloc_zeroed_slice<T>( &self, len: usize, ) -> Result<BumpBox<'a, [T]>, AllocError>

where T: FromZeros,

Allocate a zeroed object slice.

impl<A, const MIN_ALIGN: usize, const UP: bool, const GUARANTEED_ALLOCATED: bool, const DEALLOCATES: bool> Debug for BumpScope<'_, A, MIN_ALIGN, UP, GUARANTEED_ALLOCATED, DEALLOCATES>

where MinimumAlignment<MIN_ALIGN>: SupportedMinimumAlignment,

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'b, A, const MIN_ALIGN: usize, const UP: bool, const GUARANTEED_ALLOCATED: bool, const DEALLOCATES: bool> From<&'b Bump<A, MIN_ALIGN, UP, GUARANTEED_ALLOCATED, DEALLOCATES>> for &'b BumpScope<'b, A, MIN_ALIGN, UP, GUARANTEED_ALLOCATED, DEALLOCATES>

where MinimumAlignment<MIN_ALIGN>: SupportedMinimumAlignment, A: Allocator,

fn from( value: &'b Bump<A, MIN_ALIGN, UP, GUARANTEED_ALLOCATED, DEALLOCATES>, ) -> Self

Converts to this type from the input type.

impl<'b, A, const MIN_ALIGN: usize, const UP: bool, const GUARANTEED_ALLOCATED: bool, const DEALLOCATES: bool> From<&'b mut Bump<A, MIN_ALIGN, UP, GUARANTEED_ALLOCATED, DEALLOCATES>> for &'b mut BumpScope<'b, A, MIN_ALIGN, UP, GUARANTEED_ALLOCATED, DEALLOCATES>

where MinimumAlignment<MIN_ALIGN>: SupportedMinimumAlignment, A: Allocator,

fn from( value: &'b mut Bump<A, MIN_ALIGN, UP, GUARANTEED_ALLOCATED, DEALLOCATES>, ) -> Self

Converts to this type from the input type.

impl<'a, A, const MIN_ALIGN: usize, const UP: bool, const GUARANTEED_ALLOCATED: bool, const DEALLOCATES: bool> BumpAllocatorScope<'a> for BumpScope<'a, A, MIN_ALIGN, UP, GUARANTEED_ALLOCATED, DEALLOCATES>

where MinimumAlignment<MIN_ALIGN>: SupportedMinimumAlignment, A: BaseAllocator<GUARANTEED_ALLOCATED>,

impl<A, const MIN_ALIGN: usize, const UP: bool, const GUARANTEED_ALLOCATED: bool, const DEALLOCATES: bool> MutBumpAllocator for BumpScope<'_, A, MIN_ALIGN, UP, GUARANTEED_ALLOCATED, DEALLOCATES>

where MinimumAlignment<MIN_ALIGN>: SupportedMinimumAlignment, A: BaseAllocator<GUARANTEED_ALLOCATED>,

impl<A, const MIN_ALIGN: usize, const UP: bool, const GUARANTEED_ALLOCATED: bool, const DEALLOCATES: bool> NoDrop for BumpScope<'_, A, MIN_ALIGN, UP, GUARANTEED_ALLOCATED, DEALLOCATES>

impl<A, const MIN_ALIGN: usize, const UP: bool, const GUARANTEED_ALLOCATED: bool, const DEALLOCATES: bool> RefUnwindSafe for BumpScope<'_, A, MIN_ALIGN, UP, GUARANTEED_ALLOCATED, DEALLOCATES>

where MinimumAlignment<MIN_ALIGN>: SupportedMinimumAlignment, A: UnwindSafe,

impl<A, const MIN_ALIGN: usize, const UP: bool, const GUARANTEED_ALLOCATED: bool, const DEALLOCATES: bool> UnwindSafe for BumpScope<'_, A, MIN_ALIGN, UP, GUARANTEED_ALLOCATED, DEALLOCATES>

where MinimumAlignment<MIN_ALIGN>: SupportedMinimumAlignment, A: UnwindSafe,